Declining Cognitive Function May be the Result of Chronic Stress
Adult attention and learning, according to common belief, tend to decline as we age. This means that we expect to forget things, to not learn as easily as we might once have, and generally speaking, have declining cognitive function. Society has determined this as the norm. Additionally, we have been led to believe that, with aging, we lose the ability to learn new skills or even retain and assimilate new information.
New Theory Explains Declining Cognitive Function
There is, however, a new theory that suggests that this information and belief system is outdated. It proposes that if adults continued learning the way we did as children, the term ‘aging’ would need to be redefined.
The theory proposes that declining cognitive function is dependent on the learning strategies and habits developed over a lifetime. Depending on these strategies and habits, our cognitive development is either encouraged or discouraged.
If, for example, adults had to embrace the learning principles of a child, i.e. using broader learning experiences that promote growth and development, they would notice an increase in cognitive health instead of the formerly expected decline. The broader learning experience would, according to this theory, encompass the following six factors.
These factors are endemic to an infant’s learning experience:
Learning that is open-minded and input-driven
You are encouraged to explore outside your particular comfort zone, learning new patterns and skills continuously.
You have access to teachers as well as mentors who guide you in your learning, e.g. a mother teaching her child how to draw but constantly increasing the difficulty level.
A growth mindset
Where you believe you can increase your abilities with a little effort.
A forgiving environment
Mistakes and failures are fine and deemed a part of the learning process.
A serious commitment to learning
Where you are committed to mastering new skills, persevering in your efforts even when experiencing setbacks.
Learning multiple skills simultaneously
Where you do not limit the learning of new skills to one at a time but embrace many at the same time
During infancy and young childhood, these factors work together, increasing your basic cognitive abilities such as your attention, working memory, and inhibition. The same factors may work during adulthood as well.
As we move towards adulthood, however, our learning changes focus and becomes more specialized in nature. This specialization, however, has negative results for our cognitive growth, as:
We become closed minded and focus on specific knowledge driven learning
This infers we stay within our comfort zone and stick to routines.
There is no scaffolding
We no longer have access to teachers or mentors that guide our learning process.
We find ourselves in an unforgiving environment
Failure has consequences, such as losing our job. It is not seen as a means of learning.
We develop a fixed mindset
We start to believe our abilities are talents we are born with rather than something we acquired and developed with our own efforts.
We are less committed to learning
We may start something new but drop it after a while due to ‘not having enough time’ or because ‘it is too difficult’.
We learn no more than one skill at a time
Whereas infants learn a range of skills simultaneously we tend to focus, as we age, on only learning one skill (if any) at a time.
The theory thus proposes that, when taking a look at our cognitive function from infancy to late adulthood, the decline in broad learning may play a role in the cognitive aging process. If, however, the factors described were to be implemented, aging adults would be able to expand their cognitive function way past the limits we currently take as the norm.
Specialized learning seems to take over from broad learning once we become career driven. Unfortunately, as a consequence, this is the point where cognitive aging begins. Once we have become accustomed to a work environment and become efficient in what we do with regards to our activities and work expectations, we seldom vary from the mold our work environment has set for us.
While there are benefits to this type of learning attitude, e.g. it may ensure a measure of efficiency and accuracy when responding to a number of situations we may have to deal with, there are also disadvantages. This may be in the form of having made an assumption about something and being put in a position where you need to change your point of view or way of thinking. You are not accustomed to this any longer and may find changing your mindset or way of thinking difficult to master. This is not the same with broad learning where things are constantly challenged.
However, it is not only the way we learn (or do not learn) that results in declining cognitive function. Our health, especially the symptoms experienced due to stress and its implications, may play a large role in this regard.
The Role of Stress in Declining Cognitive Function
In a nutshell, the term ‘stress’ is used to describe the physiological, psychological, and environmental conditions that put so much pressure on a person that they feel they cannot adapt to it. Some of these conditions include a heavy or prolonged heavy workload, infectious diseases, intolerable conditions in your personal life, sleep deprivation, social pressure, and even constant loud noise. The stress you encounter may be short lived, or it may be chronic in nature, i.e. continuous, without giving you any relief. Generally speaking, people may ultimately respond to stress in one of two ways: you may either rise to the occasion, conquer what is causing the stress (like your work load), or you may deliver sub-par work. Each person reacts differently.
Chronic, consistent stress, however, may cause a disruption in your body’s homeostasis, i.e. balance, and result in a number of stress-related symptoms such as irritability, declining cognitive function such as memory loss as an example, skin conditions, depression, hormonal imbalance, sleep problems such as insomnia, weight gain or weight loss, bowel movement problems, etc. The reason for this is because chronic stress causes an increase in cortisol production.
The Effect of Cortisol
Enhanced cortisol production is the result of stress. It is commonly known as the fight or flight hormone and is produced by the adrenal glands, as part of the body’s hypothalamic-pituitary-adrenal (HPA) axis and is a byproduct of its NeuroEndoMetabolic (NEM) stress response. This response is automatic, and you are not able to control it.
High cortisol levels of short duration may actually have a beneficial effect on brain function as it makes you more alert, clears your brain to face whatever is coming your way, and results in your body getting ready for action.
Prolonged and possibly increased stress, however, may have long-term negative consequences resulting in symptoms such as:
Due to an increase in blood sugar levels needed as energy in order to fight or flee, the development of insulin resistance due to the pancreas having to produce increasing amounts of insulin (and possibly burning out) to deal with the increase in blood sugar.
Due to pregnenolone, the precursor hormone of most other hormones, being reserved for cortisol production – resulting in low libido, infertility, depression, and other hormone-related issues.
Due to cravings for foods high in fat, sugar, and carbohydrates due to higher insulin levels
A suppressed immune system
As high cortisol levels suppress inflammation and in turn your immune system
Declining cognitive function resulting in anxiety, depression, dementia, a decline in memory and thinking skills, and Alzheimer’s.
At some point, however, the adrenals are unable to handle the expected cortisol output and reach a state of exhaustion, commonly referred to as adrenal fatigue.
Stress and Declining Cognitive Function
High cortisol levels result in high glutamate levels. Glutamate is a neurotransmitter that creates free radicals that, in turn, may attack brain cells, causing their demise. Stress, and the corresponding higher cortisol levels, may inadvertently lead to certain lifestyle habits that actually increase your free radical load, such as not getting enough sleep, smoking in order to help you relax, alcohol abuse or misuse, following the wrong diet, e.g. eating fast foods and processed foods, and not getting enough sleep.
When stressed, certain electrical signals in the brain that are associated with facts are weakened, while areas in the brain that are associated with your emotions are strengthened, thereby making you more emotionally inclined. This may result in instances of crying for an unknown reason, mood swings, or even feelings of being ‘down’.
Stress also has an impact on your feelings of anxiety as it increases your neural responses due to a perceived ‘threat’. This results in feelings of anxiety.
It also has a negative effect on new brain cell creation. While we lose brain cells on a daily basis, new ones are constantly created. A protein called brain-derived neurotrophic factor (BDNF) is responsible for this. High cortisol levels, however, have a negative effect on the production of BDNF, with the resulting decrease in new brain cell creation. Low BDNF levels are associated with conditions such as depression, dementia, Alzheimer’s, and even schizophrenia. In other words, a declining cognitive function.
High cortisol levels are closely associated with depression. As your brain cells communicate with other body systems by means of neurotransmitters, the brain needs a balanced environment to do so optimally. Chronic stress and the accompanying high cortisol levels, however, results in a reduction of serotonin and dopamine. When dopamine and serotonin levels are uncommonly low, though, depression can develop.
People who are prone to addictions also have low levels of these two neurotransmitters. Serotonin is commonly known as the “feel good’ hormone. It is, essentially, a mood stabilizer and is responsible for maintaining a mood balance. Low serotonin levels may lead to depression.
Dopamine, on the other hand, helps with the transmission of signals from the brain to other areas of the body and acts on the sympathetic nervous system of which the HPA axis forms a part. Dopamine is usually released by the brain as a ‘reward’, result in feelings of pleasure. This is why people with low dopamine levels tend towards addictive behavior such as overeating or alcohol misuse – it gives them the same pleasurable feelings as it temporary boosts dopamine levels. However, low dopamine levels also lead to declining cognitive function as well as feelings of lethargy and a lack of any kind of enjoyment.
High cortisol levels may negatively impact the development of new neurons in your hippocampus. This is where memories are stored. This area of the brain is considered critical for your emotions, learning, and memory. It also plays a role in shutting down the NEM stress response once a perceived threat has passed. Heightened cortisol levels also cause a shrinkage of the frontal cortex which plays a role in decision making, your memory, and your behavior.
Cortisol has a negative influence on your brain’s blood-brain barrier in that is makes it more permeable. Thus toxins such as heavy metals and chemicals are able to cross over this semi-permeable filet. The result is not only declining cognitive function, but also an increased chance of developing multiple sclerosis (MS), brain cancer, and infections.
In short, stress may be a real factor in declining cognitive function.
Managing Declining Cognitive Function
Whereas Western medicine would focus on managing the symptoms associated with declining cognitive function, functional medicine looks at solving the root cause of the problem. Where declining cognitive function is the result of stress, one would thus look at managing the stressors in your life, both internal and external.
Watch your diet
By cutting out or reducing your intake of certain foods and stimulants such as sugar, coffee, alcohol, and carbohydrates, you cut out those elements that artificially give you a rush and that stimulate cortisol production.
Furthermore, adding antioxidant rich foods helps your body fight free radical damage caused by cortisol. Good examples of food rich in antioxidants include leafy green vegetables (e.g. spinach and kale), green tea, lean red beef, and fruit (e.g. blueberries).
Exercise does not need to be strenuous in order to be good for you. A daily dose of low impact exercises like tai chi, walking, or yoga is an excellent way to get your blood pumping and boost your BDNF levels.
Practice your breathing
Deep breathing exercises are great at calming you and combating stress. Meditation is also a great stress reliever as it helps you master your thoughts while working on your posture and breathing technique at the same time. Stress is often the result of what you think about. Clearing your mind of what worries you and causes you stress works wonders at helping you combat the problem.
Take time out
Consider taking time out from your body schedule for you. Do what makes you happy. Spend time with family or friends. Read a book. Do some gardening. Take up a hobby. Whatever gets your mind away from the stress, do it.
Consider taking herbal supplements
Certain herbal supplements not only help your body to build resilience, but may have a calming effect, help your body deal with cortisol, and support your overall health.
Good options include:
- Lemon balm – Improves your mood and induces a feeling of calmness that can last for up to six hours.
- Kava – Studies show that Kava lowers feelings of anxiety associated with stress. It has, however, been linked to instances of liver failure. You should talk to a healthcare specialist before trying this option, especially if you have any liver problems.
- Valerian root – Valerian root is often used in the management of sleep disorders and anxiety. Low doses taken for up to a month are considered safe. It is, however, always safer to talk to a medical specialist before using Valerian root in stress management.
It is important to consult with a professional before starting these supplements.
Paradoxical reactions are possible when the body is in advanced stages of adrenal fatigue, especially when it comes to supplements that can modulate your mood.
Consider your vitamins
- The B vitamins – The B vitamins play a role in your nervous system. They optimize brain function and cognitive activity, help with anxiety and depression, and help prevent nerve damage.
- Vitamin C – Vitamin C helps in the production of anti-stress hormones in your body.
When taking supplements of any sort, make sure that they do not clash with any medications you are currently taking. Also make sure not to drink alcohol, as it may have an effect on your body’s use of the supplements.
© Copyright 2017 Michael Lam, M.D. All Rights Reserved.
Dr. Lam’s Key Question
Does declining cognitive function have anything to do with diet?
Declining cognitive function may in certain circumstances have its root cause in heightened cortisol levels. As diet plays a role in cortisol production, it would most certainly have an impact on cognitive function.